JP2000135460A - Reverse roll coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a substrate from bending to be broken after bringing into contact with a backup roll, to properly transport the substrate by a backup roll and to form an excellent coating film by preventing the generation of the nonuniformity of a coating surface caused by raising the rear part of the substrate at the time of transporting. SOLUTION: The outside diameter of the backup roll 8 is formed to be larger than that of an applicator roll 5 and the transporting level of the substrate 6 by a transporting roller 7 is set to be almost equal to the transporting level of the substrate 6 by the backup roll 8. As a result, the substrate is prevented from the breaking caused by bending stress due to bending without raising the front end of the substrate in the transporting direction and the generation of the nonuniformity of the coating surface is prevented because the rear part of the substrate in the transporting direction is not raised on the middle of the transportation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal glass substrate, a film liquid crystal substrate, an image sensor substrate, a printed wiring substrate, a semiconductor wafer, etc., while horizontally transporting various substrates such as an applicator roll to the surface of the substrate. The present invention relates to a reverse roll coater for applying a coating liquid to a substrate surface through a peripheral surface of an applicator roll to form a coating film having a predetermined thickness by rotating the applicator roll by contacting the coating liquid.

[0002]

2. Description of the Related Art Conventionally, a reverse roll coater has been used as an apparatus for applying a coating liquid such as a photoresist liquid or a polyimide resin to the surface of various substrates such as a liquid crystal glass substrate to form a coating film having a predetermined thickness. It is used.

In such a conventional reverse roll coater, a substrate is transported by a plurality of transport rollers arranged side by side along a horizontal transport path, and the substrate is fed between an applicator roll and a backup roll thereunder. The applicator roll contacts the peripheral surface of the applicator roll with the surface of the substrate while the coating liquid supplied to the peripheral surface of the applicator roll through a coating liquid supply roll or a coating liquid supply roll unit including a plurality of rolls. The coating is applied to the surface of the substrate by rotating in the direction opposite to the transport direction of the substrate, and the coating liquid is dried to form a coating film having a predetermined thickness on the surface of the substrate.

In the conventional reverse roll coater, since the outer diameters of the applicator roll and the backup roll are almost the same, the transport level of the transport rollers for transporting the substrate is changed to the transport level of the backup roll. If you make it the same as
The applicator roll rotating in the direction opposite to the substrate transport direction may cause the substrate to be rebounded. In order to avoid this, in the conventional reverse roll coater, as shown in FIG. 6, the transport level of the transport roller 17 is about 1 m higher than the transport level of the backup roll 18.
m, so that the substrate 16 is first brought into contact with the backup roll 18 to bring it into a transport state, and then is brought into contact with the applicator roll 15.

[0005]

However, in the conventional reverse roll coater, as shown in FIG.
Since the front end 16a in the transport direction is lifted and bent after the sheet 6 comes into contact with the backup roll 18, a bending stress is generated in the substrate 16 itself, and a substrate crack may occur particularly in the thin substrate 16. there were.

Further, depending on the shape of the front end 16a of the substrate 16 in the transport direction, the resistance of the contact portion with the applicator roll 15 becomes larger than the frictional force between the backup roll 18 and the substrate 16, and the substrate 16 may not be transported properly. Was.

Further, as shown in FIG. 8, when the substrate 16 is conveyed to a position where it comes into contact with the applicator roll 15, the rear end 16b of the substrate 16 in the conveying direction is lifted. In some cases, the coating surface was uneven at an instant.

The present invention has been made in view of such a problem, and it is possible to prevent a substrate from bending and breaking after contacting a backup roll, and to properly transport the substrate by the backup roll. In addition, it is an object of the present invention to provide a reverse roll coater capable of preventing the occurrence of unevenness on the coating surface due to the lifting of the rear portion of the substrate during the transportation and forming a good coating film.

[0009]

In order to achieve the above object, a reverse roll coater according to the present invention is characterized in that the outer diameter of the backup roll is formed to be larger than the outer diameter of the applicator roll. The point is that the transfer level of the substrate by the transfer roller is set to be substantially equal to the transfer level of the substrate by the backup roll. And by adopting such a configuration, the substrate is transported while maintaining a horizontal state when transported through the gap between the backup roll and the applicator roll after the substrate abuts on the backup roll. Without the front end being lifted and flexing,
It is possible to prevent the substrate from cracking due to bending stress, and to prevent the rear end of the substrate from being lifted during transport, thereby preventing the occurrence of unevenness in the application surface. Further, since the substrate abuts on the backup roll while being maintained in a horizontal state, and is brought into a transport state by the backup roll, and then comes into contact with the applicator roll, regardless of the shape of the front end in the transport direction of the substrate, this front end and the applicator The resistance at the contact portion with the roll can be reduced, and the substrate can be properly transported by the frictional force of the backup roll.

The reverse roll coater according to claim 2 is characterized in that, in claim 1, the outer diameter of the backup roll is at least about 1.5 times the outer diameter of the applicator roll.
The point is that it is formed twice or less. And, by adopting such a configuration, the outer diameter of the backup roll is formed to an appropriate size to suppress an increase in the size of the reverse roll coater itself, and to more reliably prevent damage to the substrate during transport. Appropriate transfer of the substrate can be performed.

[0011]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIGS.

As shown in FIG. 1, a reverse roll coater 1 according to the present embodiment is provided with a liquid storage tank 2 for storing a coating liquid such as a photoresist liquid. The pickup roll 3 is rotatably supported about a horizontal axis so that a part of the peripheral surface is immersed in the photoresist liquid. A motor (not shown) is connected to the pickup roll 3, and is driven to rotate around the horizontal axis at a constant speed in the direction of the arrow. In the vicinity of the pickup roll 3, an offset roll 4 is rotatably supported in a direction indicated by an arrow around a horizontal axis, and the pickup roll 3 is freely movable toward and away from the offset roll 4. The size of the gap on the peripheral surface of the device can be adjusted. The applicator roll 5 is rotatably supported on the offset roll 4 so as to be rotatable about a horizontal axis such that the peripheral surface of the applicator roll 5 contacts the peripheral surface of the offset roll 4. A motor (not shown) is connected to the applicator roll 5 so that the applicator roll 5 is driven to rotate around the horizontal axis at a constant speed in a direction indicated by an arrow. This applicator roll 5
The application liquid supplied from the liquid storage tank 2 by the pickup roll 3 and the offset roll 4 is applied to the substrate 6.

The above-mentioned liquid storage tank 2, pickup roll 3,
A coating liquid supply mechanism for supplying and applying a coating liquid to the substrate 6 by the offset roll 4 and the applicator roll 5 is configured.

On the other hand, in the present embodiment, a substrate transport mechanism for transporting the substrate 6 to a coating liquid application position by the applicator roll 5 is provided, and the substrate transport mechanism slides the substrate 6 on the outer peripheral surface. A plurality of transport rollers 7 that are brought into contact and transported in the horizontal direction are arranged side by side in the horizontal direction, and the transport rollers 7 are located in front of the substrate 6 in the transport direction and directly below the applicator roll 5. A backup roll 8 for transporting the coating 6 to the application position is provided. From the viewpoint of more stably transporting the substrate 6, the axis of the backup roll 8 is
It is preferable that the substrate 6 is disposed so as to be located on the same line in the vertical direction with respect to the axis of the substrate 6, but may be shifted by about 5 mm to the carry-in side of the substrate 6 in order to accelerate the contact timing of the substrate 6.

Further, as shown in FIG. 2, the outer diameter of the backup roll is formed to be larger than the outer diameter of the applicator roll 5, and the transfer level of the substrate 6 by the transfer rollers 7 The level is set so as to be substantially equal to the transport level of the substrate 6 by the backup roll 8. In the present embodiment, the substrate 6
When the thickness of the backup roll 8 is 0.3 to 1.1 mm and a photoresist liquid is used as a coating liquid, the outer diameter of the backup roll 8 is about 1.5 to 4 times the outer diameter of the applicator roll 5.
In this embodiment, the outer diameter of the applicator roll 5 is formed to be 80 to 100 mm, while the outer diameter of the backup roll 8 is formed to be 150 mm or more. However, the outer diameter of the backup roll 8 is set not to exceed 400 mm so that the apparatus does not become too large.

Since the outer diameter of the backup roll 8 is formed to be larger than the outer diameter of the applicator roll 5 as described above, the transfer level of the substrate 6 by the transfer roller 7 can be reduced by the transfer of the substrate 6 by the backup roll 8. The level can be set to be substantially equal to the level, and the substrate 6 is transported by the backup roll 8 while maintaining the horizontal state.

In this embodiment, the applicator roll 5
Of the backup roll 8 is 3 mm.
When the transfer roller 7 is formed to have a thickness of 00 mm, the transfer level of the transfer roller 7 is set to be 0.2 m higher than the transfer level of the backup roll 8.
If the distance is set to be lower by about m, the influence of bending stress or the like acting on the substrate 6 can be neglected.

Next, the operation of the present embodiment will be described.

In the reverse roll coater 1 of the present embodiment, first, a pickup roll 3 constituting a coating liquid supply mechanism is driven to rotate around a horizontal axis in a direction indicated by an arrow in FIG. It is scraped up from the inside of the liquid storage tank 2 and applied on its peripheral surface in the form of a film. And
The pick-up roll 3 moves around the horizontal axis in the vicinity as shown in FIG.
The peripheral surface is brought into contact with the offset roll 4 that is rotatingly driven at a constant speed in the direction of the arrow, and an appropriate amount of the coating liquid is transferred onto the peripheral surface of the offset roll 4 from the peripheral surface. Also,
The offset roll 4 includes an applicator roll 5
Is rotated by a motor (not shown) in the direction opposite to the transport direction of the substrate 6 indicated by the arrow in FIG. 1 around the horizontal axis while contacting the peripheral surface thereof. Is transferred to the peripheral surface of the applicator roll 5 again.

The substrate 6 is transported in a horizontal direction at a constant speed by a plurality of transport rollers 7 constituting a substrate transport mechanism. After entering the transport state, the peripheral surface of the applicator roll 5 comes into contact with the surface of the substrate 6, and the substrate 6 is transported forward through the gap between the applicator roll 5 and the backup roll 8. At this time, since the outer diameter of the backup roll 8 is formed to be larger than the outer diameter of the applicator roll 5, the front end 6a of the substrate 6 in the transport direction first comes into contact with the peripheral surface of the backup roll 8, and 8
Is transported by the frictional force in accordance with the rotational drive of.
Further, since the transport level of the transport roller 7 is set substantially equal to the transport level of the backup roll 8, the substrate 6 cannot be lifted at the front end 6a in the transport direction.
It is transported while maintaining a substantially horizontal state. And the substrate 6
Is transported through the gap between the applicator roll 5 and the backup roll 8, the coating liquid attached to the peripheral surface of the applicator roll 5 is transferred from the peripheral surface of the applicator roll 5 to the surface of the substrate 6, and A coating film having a predetermined thickness is formed on the surface of the substrate.

Therefore, according to the present embodiment, the outer diameter of the backup roll 8 is formed to be larger than the outer diameter of the applicator roll 5, and the transport level of the substrate 6 by the transport roller 7 is controlled by the backup roll 8. Since it is set almost equal to the transport level of the substrate 6,
When the substrate 6 is conveyed while maintaining a horizontal state while being conveyed in the gap between the backup roll 8 and the applicator roll 5 after the substrate 6 abuts on the backup roll 8, the substrate 6 is bent and cracked by bending stress. Can be prevented, and the occurrence of uneven coating surface due to the lifting of the substrate rear end 6b during the transfer can be prevented.

Further, the substrate 6 in the present embodiment comes into contact with the applicator roll 5 after being brought into contact with the backup roll 8 while being kept in a horizontal state and being brought into a state of being transported by the backup roll 8, so that the substrate 6 is transported. Regardless of the shape of the front end 6a in the direction, the resistance at the contact portion between the front end 6a and the applicator roll 5 can be reduced, and the friction between the backup roll 8 and the substrate
Can be transported. For example, even a substrate 6 having an end 6a shaped as shown in FIGS. 3 to 5 can be transported reliably.

The present invention is not limited to the above-described embodiment, but can be variously modified as needed.

[0024]

As described above, according to the reverse roll coater of the present invention according to the first aspect, the front end of the substrate in the transport direction is not lifted, and it is possible to prevent the substrate from being cracked by bending stress due to bending. However, since the rear end of the substrate in the transport direction is not lifted during the transport, it is possible to prevent the application surface from being uneven. Also,
Regardless of the shape of the front end in the transport direction of the substrate, the resistance at the contact portion between the front end and the applicator roll can be reduced, and the substrate can be properly transported by the frictional force of the backup roll.

Further, according to the reverse roll coater according to the second aspect, in addition to the effect of the first aspect, damage to the substrate during transport is more reliably achieved while suppressing the size of the reverse roll coater itself. , And proper conveyance of the substrate can be executed.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a reverse roll coater according to the present invention.

FIG. 2 is a side view showing a comparison between the outer diameter of a backup roll and the outer diameter of an applicator roll in the present embodiment.

FIG. 3 is a schematic side view illustrating an example of a shape of a front end in a transport direction of a substrate that can be transported according to the present embodiment.

FIG. 4 is a schematic side view showing another example of the shape of the front end in the transport direction of a substrate that can be transported according to the present embodiment.

FIG. 5 is a schematic side view showing another example of the shape of the front end in the transport direction of the substrate that can be transported according to the present embodiment.

FIG. 6 is a schematic side view showing a positional relationship between a substrate transport level of a backup roll and a substrate transport level of a transport roller in a conventional reverse roll coater.

FIG. 7 is a schematic side view showing a state in which the substrate abuts on a backup roll and the front end in the transport direction is lifted in FIG. 6;

FIG. 8 is a schematic side view showing a state in which a central portion in the transport direction of the substrate comes into contact with a backup roll and a high end in the transport direction is lifted in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reverse roll coater 5 Applicator roll 6 Substrate 7 Transport roller 8 Backup roll

Claims (2)

[Claims] A plurality of transport rollers for transporting a substrate are arranged in parallel in a horizontal direction, and a backup roll for transporting a substrate transported from these transport rollers to a coating liquid application position is disposed forward of the transport rollers in the transport direction. An applicator roll for transferring a coating liquid from the peripheral surface to the surface of the substrate by rotating the substrate in a direction opposite to the transport direction of the substrate and bringing the peripheral surface into contact with the surface of the substrate above the backup roll In the reverse roll coater, the outer diameter of the backup roll is formed to be larger than the outer diameter of the applicator roll, and the transfer level of the substrate by the transfer roller is substantially equal to the transfer level of the substrate by the backup roll. A reverse roll coater characterized by being set to be equal. 2. The reverse roll coater according to claim 1, wherein the outer diameter of the backup roll is formed to be about 1.5 times to 4 times the outer diameter of the applicator roll.